{"id":"CVE-2026-23215","summary":"x86/vmware: Fix hypercall clobbers","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/vmware: Fix hypercall clobbers\n\nFedora QA reported the following panic:\n\n  BUG: unable to handle page fault for address: 0000000040003e54\n  #PF: supervisor write access in kernel mode\n  #PF: error_code(0x0002) - not-present page\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20251119-3.fc43 11/19/2025\n  RIP: 0010:vmware_hypercall4.constprop.0+0x52/0x90\n  ..\n  Call Trace:\n   vmmouse_report_events+0x13e/0x1b0\n   psmouse_handle_byte+0x15/0x60\n   ps2_interrupt+0x8a/0xd0\n   ...\n\nbecause the QEMU VMware mouse emulation is buggy, and clears the top 32\nbits of %rdi that the kernel kept a pointer in.\n\nThe QEMU vmmouse driver saves and restores the register state in a\n\"uint32_t data[6];\" and as a result restores the state with the high\nbits all cleared.\n\nRDI originally contained the value of a valid kernel stack address\n(0xff5eeb3240003e54).  After the vmware hypercall it now contains\n0x40003e54, and we get a page fault as a result when it is dereferenced.\n\nThe proper fix would be in QEMU, but this works around the issue in the\nkernel to keep old setups working, when old kernels had not happened to\nkeep any state in %rdi over the hypercall.\n\nIn theory this same issue exists for all the hypercalls in the vmmouse\ndriver; in practice it has only been seen with vmware_hypercall3() and\nvmware_hypercall4().  For now, just mark RDI/RSI as clobbered for those\ntwo calls.  This should have a minimal effect on code generation overall\nas it should be rare for the compiler to want to make RDI/RSI live\nacross hypercalls.","modified":"2026-04-24T08:29:12.195125966Z","published":"2026-02-18T14:21:52.515Z","related":["SUSE-SU-2026:1573-1","SUSE-SU-2026:21237-1","openSUSE-SU-2026:20572-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23215.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2687c848e57820651b9f69d30c4710f4219f7dbf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2f467a92df61eb516a4ec36ee16234dd4e5ccf00"},{"type":"WEB","url":"https://git.kernel.org/stable/c/feb603a69f830acb58f78d604f0c29e63cd38f87"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23215.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23215"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"34bf25e820ae1ab38f9cd88834843ba76678a2fd"},{"fixed":"2f467a92df61eb516a4ec36ee16234dd4e5ccf00"},{"fixed":"feb603a69f830acb58f78d604f0c29e63cd38f87"},{"fixed":"2687c848e57820651b9f69d30c4710f4219f7dbf"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23215.json"}}],"schema_version":"1.7.5"}